Goals: The European Space Agency's Rosetta is the first mission designed to orbit and land on a comet. It consists of an orbiter and a lander -- called Philae. The two spacecraft carry 20 science instruments to make a detailed study of comet 67P/Churyumov-Gerasimenko for two years as it approaches our sun.

Accomplishments: In August 2014, Rosetta became the first spacecraft to orbit a comet when it joined comet 67P/Churyumov-Gerasimenko on it's journey around the sun. On 12 November 2014, Rosetta scored another historic first when its Philae probe successfully landed on the surface of the comet and began sending back images and data.